Exposure method

Abstract

An exposure method includes the steps of providing a mask that arranges a contact-hole pattern and a pattern smaller than the contact-hole pattern, and illuminating the mask using plural kinds of light so as to resolve the contact-hole pattern and restrain the smaller pattern from resolving on an object to be exposed via a projection optical system, wherein the following conditions are met A=−1.7k 1 +C1, 1.2≦C1≦1.3, 0.5≦B≦0.55 and B≦A−0.1, 0.80≦σ≦0.9 and σ≧A+0.1, k 1 =(L/λ)NA, where k 1 is resolving power, L is a hole diameter of the contact-hole pattern, λ is a wavelength for exposure, NA is a numerical aperture of the projection optical system, σ is a ratio of a numerical aperture of an illumination optical system to the numerical aperture of the projection optical system, A and B are distances from two orthogonal axes to a boarder of a light-shielding part in an effective light source for illumination of plural kinds of light, the light-shielding part being symmetrical with respect to the two orthogonal axes.

1. An exposure method comprising the steps of:
 providing a mask that arranges a contact-hole pattern and a pattern smaller than the contact-hole pattern; and 
 illuminating the mask by using an effective light source so as to resolve the contact-hole pattern and restrain the smaller pattern from resolving on an object to be exposed via a projection optical system, 
 wherein the following conditions are met:
     A =−1.7 k   1   +C 1, 1.2 ≦C 1≦1.3 
   0.5 ≦B ≦0.55 and  B≦A −0.1 
   0.80≦σ≦0.9 and σ≧ A +0.1 
     k   1 =( L /λ) NA,   
 
 where k 1  is resolving power, L is a hole diameter of the contact-hole pattern, λ is a wavelength for exposure, NA is a numerical aperture of the projection optical system, σ is a ratio of a numerical aperture of an illumination optical system to the numerical aperture of the projection optical system, A and B are distances from two orthogonal axes to a boarder of a light-shielding part in said effective light source, the light-shielding part being symmetrical with respect to the two orthogonal axes. 
 
     
     
       2. An exposure method according to  claim 1 , wherein conditions A=−1.7k 1 +1.25, k 1 ≦0.4, B=0.55, σ=0.85 are met irrespective of a critical dimension. 
     
     
       3. An exposure method comprising the steps of:
 providing a mask that arranges a contact-hole pattern and a pattern smaller than the contact-hole pattern; and 
 illuminating the mask using plural kinds of light so as to resolve the contact-hole pattern and restrain the smaller pattern from resolving on an object to be exposed via a projection optical system, 
 wherein the following conditions are met:
     A =1/(4 k   1 )− C 2/(4 k   1 ) 2 , 0.07 ≦C 2≦0.20 
   0.5 ≦B ≦0.55 and  B≦A −0.1 
   0.80≦−σ≦0.9 and σ≧ A +0.1 
     k   1 =( L /λ) NA,   
 
 where k 1  is resolving power, L is a hole diameter of the contact-hole pattern, λ is a wavelength for exposure, NA is a numerical aperture of the projection optical system, σ is a ratio of a numerical aperture of an illumination optical system to the numerical aperture of the projection optical system, A and B are distances from two orthogonal axes to a boarder of a light-shielding part in an effective light source for illumination of plural kinds of light, the light-shielding part being symmetrical with respect to the two orthogonal axes. 
 
     
     
       4. A device manufacturing method comprising the steps of:
 exposing a pattern formed on a reticle onto an object by using an exposure method; and 
 performing a predetermined process for the exposed object, 
 wherein the exposure method includes the steps of providing a mask that arranges a contact-hole pattern and a pattern smaller than the contact-hole pattern, and illuminating the mask using plural kinds of light so as to resolve the contact-hole pattern and restrain the smaller pattern from resolving on an object to be exposed via a projection optical system, wherein the following conditions are met:
     A =−1.7 k   1   +C 1, 1.2 ≦C 1≦1.3 
   0.5 ≦B ≦0.55 and  B≦A −0.1 
   0.80≦σ≦0.9 and σ≧ A +0.1 
     k   1 =( L /λ) NA,   
 
 where k 1  is resolving power, L is a hole diameter of the contact-hole pattern, λ is a wavelength for exposure, NA is a numerical aperture of the projection optical system, σ is a ratio of a numerical aperture of an illumination optical system to the numerical aperture of the projection optical system, A and B are distances from two orthogonal axes to a boarder of a light-shielding part in an effective light source for illumination of plural kinds of light, the light-shielding part being symmetrical with respect to the two orthogonal axes. 
 
     
     
       5. A device manufacturing method comprising the steps of:
 exposing a pattern formed on a reticle onto an object by using an exposure method; and 
 performing a predetermined process for the exposed object, 
 wherein the exposure method includes the steps of providing a mask that arranges a contact-hole pattern and a pattern smaller than the contact-hole pattern, and illuminating the mask using plural kinds of light so as to resolve the contact-hole pattern and restrain the smaller pattern from resolving on an object to be exposed via a projection optical system, 
 wherein the following conditions are met:
     A =1/(4 k   1 )+ C 2/(4 k   1 ) 2 , 0.07 ≦C 2≦0.20 
   0.5 ≦B ≦0.55 and  B≦A −0.1 
   0.80≦σ≦0.9 and σ≧ A +0.1 
     k   1 =( L /λ) NA,   
 
 where k 1  is resolving power, L is a hole diameter of the contact-hole pattern, λ is a wavelength for exposure, NA is a numerical aperture of the projection optical system, σ is a ratio of a numerical aperture of an illumination optical system to the numerical aperture of the projection optical system, A and B are distances from two orthogonal axes to a boarder of a light-shielding part in an effective light source for illumination of plural kinds of light, the light-shielding part being symmetrical with respect to the two orthogonal axes.